The present invention relates to an illumination apparatus and a liquid crystal display apparatus. In particular, the present invention relates to an illumination apparatus suitable to a semi-transmissive liquid crystal display apparatus, and a semi-transmissive liquid crystal display apparatus incorporated with this illumination apparatus.
In recent years, technological progress relating to the liquid crystal display apparatus has been significant. The liquid crystal display apparatus is incorporated also into a mobile phone, a portable personal computer etc., in addition to stationary display. Accordingly, in addition to higher performance of the liquid crystal display apparatus, compact sizing of the liquid crystal display apparatus itself has also been desired strongly. In particular, with accompanying the desire for thinner type of the liquid crystal display apparatus, thinner type of a back light part itself, which functions as a light A source of the liquid crystal display apparatus, has also been desired strongly.
As the back light part of the liquid crystal display apparatus, there has known conventionally an LED (Light Emitting Diode) or a system for guiding outgoing light from a cold-cathode tube to a liquid crystal panel part via a light guide plate (for example, refer to JP-A-2003-330007). However, in order to make uniform intensity distribution of outgoing light from the light guide plate, it is necessary to secure a certain thickness of the light guide plate, which makes difficult to achieve sufficient thinning of the back light part.
On the other hand, there has also been developed technology aiming at thinning of the back light part by utilization of an organic electroluminescence (hereafter, organic EL (organic electroluminescence)) (refer to JP-A-2003-59641, JP-A-2006-318807). However, because the directivity of the light emitted from a light emitting part of the organic EL is low, enhancement of light utilization efficiency in a display apparatus is inhibited, by which higher brightness or power saving of the liquid crystal display apparatus cannot be achieved.
In view of this point, in JP-A-2003-59641, a micro lens array element is arranged on the upper part electrode, which is present on a light emission layer. In JP-A-2006-318807, a micro lens array is arranged on the upper part electrode, which is present on a light emission layer